Experiments and Model Computation of Cylindrical Shock Waves with Time-Resolved Deformation and Fragmentation

Abstract

Since real converging shock waves are not perfectly symmetric at least a two-dimensional description of their properties is necessary, as can be seen, e.g., from the experiments of K. Takayama, H. Kleine and H. Grönig (1987). Recently, H. Kleine performed experiments with cylindrical shock waves in the Perry-Kantrowitz type of shock tube of the Shock Wave Laboratory, Aachen. The focusing process was investigated by means of optical methods. Single photos with a high resolution were taken as well as series of pictures obtained from a time-resolved visualization. Our two-dimensional computations have been successful in describing the properties of converging shock waves and, e.g., also contributed to the explanation of the nature of the developing shock fragmentation (Demmig and Petersen 1991). In order to achieve computational results for specific experiments the first snapshot of the shock entering the test section was taken as the initial configuration. The computation then yields snapshots of the physical quantities of the converging wave which can be evaluated in the form of isopycnics, shock front contours, visualization of fragmentation etc., to be compared directly with the corresponding snapshot of a single experiment.